1. Field of the Invention
The present invention relates generally to optical equipment, and more particularly to a laser block beam splitter system for microscopes suitable for protecting the viewing stations from laser light radiation.
Medical and research microscopes frequently incorporate beam splitter assemblies to permit additional viewing, video and 35 mm camera attachments. Commonly available beam splitters have two optical trains and provide two lateral optical viewing ports in addition to the primary viewing port. Such beam splitters are available commercially from microscope suppliers such as Carl Zeiss, Inc., Leica, Storz and Topcon.
In order to safely use a laser while viewing through a microscope, the prior art has provided a mechanical shutter assembly to be mounted between the beam splitter and the microscope body. Such mechanical shutter assemblies are available commercially from laser suppliers such as Coherent, Laserscope, Sharplan, Nidek and Carl Zeiss, Inc.
While functional and useful, such beam splitter and mechanical shutter assembly combinations restrict the view of the primary and lateral viewing ports when the laser is activated. The restricted view is caused by the mechanical shutter assembly which introduces a beam blocking device into both optical trains when the laser is activated.
A particular concern is the desire to provide continual unobstructed viewing to all viewing stations while a laser is activated. With the present equipment, such continual unobstructed viewing is not possible.
An additional concern is the reliability of a mechanical shutter assembly to perfectly activate and deactivate at the desired moment of use. With the present mechanical shutter assemblies, there is the ever present possibility of non-function due to electronic or mechanical failure. Such a non-function could result in severe eye injury to the operator.
Another concern is keeping the physical mass of the microscope, beam splitter and laser protection mechanism to a minimum. When the physical mass is increased, the operating comfort and efficiency of the primary and lateral stations are compromised.
For these reasons, it would be desirable to provide a beam splitter with an integrated laser safety filter. Such a system would provide continual, safe and unobstructed viewing to the viewing stations during laser activation. Also, such a system would eliminate the possibility of electronic and mechanical failures and reduce the physical mass of the microscope assembly when using a laser.
2. Description of the Background Art
A slit lamp microscope for observing eye tissue having linear polarizers is shown in U.S. Pat. No. 4,877,321. A medical dose-integrating device for measuring the illumination exposure of light-sensitive organs is shown in U.S. Pat. No. 4,657,013. A true multi-color laser scanning confocal imaging system for microscopes is shown in U.S. Pat. No. 5,127,730. A medical apparatus for detecting ophthalmic diseases using lasers is shown in U.S. Pat. No. 4,711,542. A medical laser optical delivery device having a blocking shutter is shown in U.S. Pat. No. 4,633,872. An optical head for observation and treatment of an eye with a laser is shown in U.S. Pat. No. 4,499,897. A medical laser ophthalmic device having a safety stop shutter is shown in U.S. Pat. No. 4,561,436. A system for precision laser surgery is shown in U.S. Pat. No. 5,098,426. A confocal scanning laser microscope having no moving parts is shown in U.S. Pat. No. 4,827,125. A beam splitter having three identical optical trains and four viewing stations is shown in U.S. Pat. No. 4,688,907.